Snow Leopard’s “Wake on Demand” could lead to Apple TV bliss

If you are using Snow Leopard and have some newer Apple hardware, there's a …

With the release of Mac OS X 10.6 Snow Leopard, Apple has introduced a new wake on network activity feature called "Wake on Demand" that uses Bonjour to to alert other machines on a network that their services are being requested. Perhaps most intriguing is the fact that the feature works over wireless networks as long as certain hardware requirements are met.

To use the technology over a wired network, a user must have either a 2007 (or newer) AirPort Extreme Base Station or a 2008 (or newer) Time Capsule with the most recent firmware installed, according to MacUser. If wake on WiFi activity is really what you're jonesing for, then you'll probably need a Mac released in 2009. Although Apple hasn't released an official list yet, MacUser found that machines created before then didn't seem to work. If you want to check if your machine supports Wake on Demand over WiFi you can check in System Preferences > Network > Airport, and then look under Wake on Wireless.

Potential uses for the tech include sparsely used file servers, or machines sharing printers or scanners, for instance. Right now, it's unclear if the tech can be used to awaken portables that have their lids closed, but we can imagine arguments both for and against that.

What seems to be true is that one potentially popular use—accessing iTunes shares for use with an Apple TV or even another Mac—may not be immediately possible. After all, iTunes only sees libraries being shared from active machines running iTunes with sharing enabled. It seems it would be necessary to first awaken a machine some other way before accessing the library.

A potential workaround for this may be to use an alias pointing to a share located on the sleeping machine. This way, you could awaken it and just always have iTunes running on that machine. Since opening a share from an Apple TV isn't something most people can do easily, though, this method wouldn't work. What would be ideal is if Apple released a version of iTunes or Front Row that remembers recently shared libraries, allowing it to locate and awaken the appropriate machines based on previous internal IP addresses. That is, of course, if the AppleTV's hardware and software supported the new functionality.

You will be able to read more about "Wake on Demand" and just about every other feature in Ars Technica's upcoming in-depth review of Snow Leopard, which should hit sometime early next week.